Damper assembly



April 30, 1957 E. R. COOPER DAMPER ASSEMBLY Filed March 30, 1953 L35INVENTOR EzgeneR. loo r ATTORNEY United States Patent DAMPER ASSEMBLYEugene R. Cooper, Asheville, N. C.

Appfication March 30, 1953, Serial No. 345,313

3 Claims. (CI. 98-41) a diffuser of some type is mounted in the ceilingopening so that the blast of air issuing into the room will not be feltby a person directly beneath the opening. Such diffusers are availablein a wide variety of sizes and designs and are well known in the art.

Heretofore no provision has been made for automatically controlling theamount of air entering each room through such a ceiling opening ordiffuser. Most diffuser units used in ceiling openings are provided witha manual adjustment for controlling the flow of air through the unit,but such manual adjustment is necessarily difficult and unsatisfactoryin view of the remote location of the unit and since it requiresfrequent adjustment. The present invention is concerned with a methodfor eliminating these difiiculties.

This invention comprises a damper assembly which may be readilyconnected to a duct above a ceiling diffuser for the purpose ofautomatically controlling the amount of air passing from the ductthrough the ceiling diffuser. The damper is controlled by a thermostatmounted within the room below.

Details of the invention will be explained by reference to theaccompanying drawing, wherein:

Figure 1 is a perspective of one embodiment of the invention showing thedamper in closed position.

Figure 2 is a sectional view taken along the line 2 2 in Figure 1 andshowing the assembly of Figure 1 mounted in an air conditioning system.In Figure 2 the damper is in open position.

Referring now to Figure 1, there is shown a base member 1 constructed ofsheet metal and having mounted thereon a damper 2. The damper comprisesa substantially square thin sheet of sheet metal hinged at ,3 so that itmay be raised to expose an opening (not shown) in base member 1 directlybeneath the damper 2. Mounted on base member 1 adjacent hinge 3 isU-shaped sup.- porting member 4. Supporting member 4 is provided withtwo aligned holes, one near the top of each vertical leg of supportingmember 4. There is also mounted on base member 1 an electrical controlmotor and related reduction gear assembly 5, provided with a drivenshaft 6. Shaft 6 passes through the two aligned openings in supportingmember 4. Shaft 6 is biased toward connecting socket member 7 on gearassembly by means of a spring 8. Spring 8 is concentrically disposedaround shaft 6 and is normally held under slight compression by means ofcotter key 9 and one of the upright legs of supporting member 4. Thepurpose of spring 8 will be discussed further below. The free end ofshaft 6 is provided with a radial extension 10. Mounted onTextension 10is a rotatable wheel or sheave 11. A cable 12 which passes over sheave11 is connected at 13 to damper 2 and at 14 to the base member 1, asshown. It will thus be apparent that as the shaft 6 rotates in aclockwise direc-. tion (looking toward the motor from the shaft) sheave11 will be carried in a clockwise direction through the arc defined bythe extension 10 with the result that cable 12'.

will be lifted and damper 2 will be opened. With the damper open, iftheshaft 6 rotates an additional one-half revolution in a clockwisedirection, the damper will be closed.

Electric control motor and related reduction gear assembly 5 is astandard type electric janitor control motor, commercially available,and is adapted to rotate shaft 6 approximately one-half of a completerevolution in response to a signal from a standard thermostat 15.

Such a secondary transformer type control motor is commerciallyavailable from the Minneapolis Honeywell Corporation, Minneapolis,Minnesota, and is well kown in the art of air conditioning and heating.The thermostat 15 will, of course, be mounted in the room below thedamper. nected to supply the proper voltage to the motor and reductiongear assembly 5.

The method in which this automatic damper-operates is believed to beobvious from the foregoing description.

If the installation is to be used in a heating system,-

when the temperature in the room reaches the lower limit at which thethermostat 15 is set, the electric m'otor and reduction gear assembly 5receives electric current and rotates shaft 6 in such a manner as toopen damper 2. When the temperature in the room satisfies thethermostat, the motor and reduction gear assembly 5 rotates the shaft 6an additional one-half of a revolution; closing damper 2. 1 v 1 Animportant advantage of the present invention is that it provides acompletely assembled damper unit ready to be attached to a duct. It willbe observed in the drawing that base 1 is provided with holes 17, 18,19,

20, etc. so that it maybe readily connected to the bottom of the duct bymeans of sheet metal screws. The opening cut in the bottom of the ductis only large enough to accommodate that part of the base member Icarrying the damper 2 and U-shaped supporting member 4. The motor andgear assembly 5 is, then, disposed outside the duct. This permitssubsequent servicing and prevents dirt or grease from the motor beingtransferred to the air in the duct. The shaft 6, of course, must passthrough the side of the duct in the completed assembly, and it is inthis connection that the spring 8 surrounding the shaft 6 has itsprimary use.

The installation in a duct of the complete damper unit shown in Figure 1is accomplished as follows: First, an opening is cut in the bottom ofthe duct adjacent one side thereof of sufficient size to accommodatethat part of the base member carrying the damper and U-shaped supportingmember. This opening is cut adjacent one side of the bottom of the ductin order that the shaft may protrude through that side of the duct andmake connection with the motor and gear assembly 5 mounted outside theduct on the base member 1. Next, a small hole is cut in the side of theduct at the proper location to accommodate the shaft 6. Then, to mountthe base member and its component parts on the duct, the shaft isdisconnected at the motor and pressed outwardly away from the motor,compressing spring 8. With the shaft in this condition, the base member1 is placed in position over the opening in the bottom of the duct. Thedamper and the U-shaped supporting member, of course, fit up inside theduct and the shaft 6, biased by the compressed spring, slides along theside of the duct until it Patented Apr. '31 1957 4 If necessary, atransformer 16 may be con-'- it slips through the hole and.may beconnected to the motor and gear assembly outside the duct throughconnecting. socket inembe'rl 7.. The base: niembenli-isthen connected tothe duct by meansofscreWs and thecasseth-Z' bl'y is.cornplete. .Verysatisfactoryresults :areobtained by the? use of a shafthaving ahexagonal head or end in combination with a socket member havingahexagonalshaped recess therein.

recess to provide a drivingconnection between the motor and the 'shaft.

Figure 2 shows the assembly of Figure I mounted ona duct with the damperinlopen position. The'base unit,

, horizontal arrows, is such that whenthe. damper 2 is opened a portionof the air will be diverted by the damper Zan'd directed via conduit 23through difiuser 24 into the room below. When damper 2 is closed, ofcourse, al l' of the air flowing through the duct 20 will by-passconduit, 23, The motor, andgear assembly,;n ot shown in Figure- 2, islocated outside the-duct 20 with the shaft extending through the 'sidewall of the duct. In this location, the motor and gear assembly areaccessible for servicing or. repair and are completely isolated from themoving air in the duct.

The assembly illustrated and described may easily be i installed eitherin an existing'air distributing system or in a new system being built.While a single embodiment of the invention has been described, it willbe. apparent that various changes and modifications may be'rnade thereinwithout departing from the spirit of the invention.

What is claimed is: 1. In an air distributing system, an air supply ductextending horizontally above the ceiling in a room, said ducthaving anopening inthe lower side thereof, a-;base

member attached-to the outsideof said duct and. provided with-Tanopening infiuid communication with the opening in said duct, a damperconnected to saidbase member and disposed inside said duct, anelectricgmotor providing a source of rotaryp'ower disposed outside saidduct, a thermostatic control forsaid motor, a shaftconnected in drivingrelation to said motor, means responsive to the rotational movement ofsaid shaft to cause said damper to open and close'saidopening in saidbase member,

means to disconect said shaft from saidimotor to permit The springmember, of course, tends to. constantly urge the end of the shaft intothe longitudinal movementof saidrshaft and resilient means urging saidshaft toward said motor.

2. In an air distribution system, an air supply duct extendinghorizontally above the ceiling in a room, said duct having an opening inthe lower side thereof, a base member attached to the outside of saidduct and provided with an opening in fluid communication with theopening in said duct, a fiat damperdoor pivotallyconnected to said basemember and adapted to intercept a portion of the air flowing throughsaid duct when said door is in open position, an electric motorproviding a source of rotary power disposed outside said duct andattached to said base member, a shaft supporting element connected tosaid base member and disposed inside said duct, a rotatable shaftdetachably connected to said motor and extending from said motor throughthe side of said duct and supported by said shaft supporting element,and means connecting-said shaft tosaid door to cause said door to openand, close in response to rotary movement by said shaft.

3. In combination; a flat metal basemember having an opening therein, aflat door member pivotally connected to said base member and adapted tofit over said opening, an electric motor providing a source of rotarypower mounted near the edge of said base member, a shaft supportingelement connected to said base member, a rotatableshaft supported bysaid elementand extending between said element and said m'otor, an armextending normal to the axis of said shaft and connected tosaid shaft, asheave connected to said arm, the axis of said sheave beingsubstantially parallel to the'axis of said shaft, resilient means urgingsaid shaft toward said motor, means to connect said shaft to'said motorfor rotation thereby and means to disconnect said shaft from said motorto permit longitudinal movement of said shaft, and a flexible cableextending from said door to said base member, said cable beingconnectedto said door and said base member and adapted to intercept a groove onsaidsheave whereby upon rotation of said shaft said door is opened forclosed.

References Cited in the file of this patent UNITED STATES PATENTS

